[AR] Re: OT laser propulsion and power satellites
- From: Keith Henson <hkeithhenson@xxxxxxxxx>
- Date: Tue, 15 Oct 2013 19:14:50 -0700
On Tue, Oct 15, 2013 at 4:10 PM, Jake Anderson <jake@xxxxxxxxxxxxxxx> wrote:
> It seems as though one would be better served by building sea dragon to
> launch this rather than skylon.
> you need what 20 sea dragons to get that mass into orbit?
500,000 tons per year/~500 tons per launch, 1000 sea dragon launches
per year, ~3 per day. That's to LEO, power sat parts need to be
delivered to GEO which takes a 2.5 x multiplier, or 2500 launches a
year. And you need to consider growth to 20 times that much or 50,000
launches per year if power sats are to replace fossil fuels. At 60
tons per hour, the Skylon/laser setup will deliver more than a Sea
Dragon LEO payload to GEO in less than ten hours.
> Once you are done I think you might have a more useful/novel end result,
> launching the entire ISS in one hit with 100T to spare?
I think it would have to be tightly packed and unfolded on orbit.
Power satellites with dimensions in the 5-10 km range are just
impossible to launch in one piece.
> I'd be curious to see if a modern take on sea dragon could do better in
> terms of construction price, filament wound fibreglass rather than welded
> steel might well reduce the labour costs of making the thing.
>
> I can see skylon being the taxi of space, great for people and small
> cargoes, because you can test the crap out of it. Not the vehicle of choice
> to deliver a power station however.
I am not welded to Skylon. If you have a direction that will cost
less and be less risk to build, I am extremely interested. However,
that's not going to be easy. Burning hydrogen and air followed by
using laser heated hydrogen for reaction mass will get close to 20% of
the gross takeoff mass into LEO as payload (17% structure).
The trouble with this scheme, as you point out, is small unit size to
GEO, 20 tons three times an hour, which delivers 500,000 tons per year
flying Skylons off one runway. The payload size is ultimately set by
the propulsion laser and the fact that you have to get the vehicle
into orbit before it falls out of the sky. But it does take quite an
industrial base at GEO to rework second stages into power satellite
parts.
Keith
> On 16/10/13 02:08, Keith Henson wrote:
>>
>> On Mon, Oct 14, 2013 at 10:40 PM, Derek Clarke <derek_c@xxxxxxxxx> wrote:
>>>
>>> Nice try, but no cigar. That programme is far too expensive.
>>
>> So far, the technical people say it is to expensive and the finance
>> people say it can't be done for technical reasons.
>>
>> Now, *I* have no idea of how to raise that scale of money, but as
>> energy project go, it is about half the size of the largest and there
>> are several of the same size, mostly LNG projects. If the Chinese do
>> it, $60 B is twice the cost of Three Gorges Dam.
>>
>>> Then there are
>>> the implications of large numbers of multigigawatt lasers.
>>
>> That I clearly state in the talk. Even one of them has huge
>> implications. Someone with experiences in military studies says the US
>> will attempt to destroy any Chinese propulsion laser. If the Chinese
>> were doing it jointly with the Indians would we still destroy it? Is
>> it in the interest of the US for the Chinese to get off coal? From the
>> viewpoint of the US, how do propulsion lasers differ in kind from
>> Predator drones and Hellfire missiles?
>>
>>> It was also not clear why you go to the expense of developing Skylon just
>>> to
>>> launch the first satellite.
>>
>> The second generation Skylon, the one with the laser hydrogen heaters
>> is required to get the long term transport cost down. It's just too
>> much of a technological jump at one time so we need the original
>> version. The cargo needed for the first microwave powered propulsion
>> laser is in the ten thousand ton range. That will take ~1000 flights
>> of something to get it there. At two hundred flights per vehicle,
>> that will take 5-6 Skylons and about a year. I don't know any less
>> expensive way to get that much into space, especially when we need the
>> engineering experience of flying a couple of Skylons a day. Working
>> up to 3 flights an hour is going to be an interesting task.
>>
>> Keith
>>
>>> On Tuesday, October 15, 2013, Keith Henson wrote:
>>>>
>>>> http://youtu.be/qCiw99yRBo8
>>>>
>>>> Talk I gave at Google in July.
>>>>
>>>> Keith
>>>>
>>
>> On Mon, Oct 14, 2013 at 10:40 PM, Derek Clarke <derek_c@xxxxxxxxx> wrote:
>>>
>>> Nice try, but no cigar. That programme is far too expensive. Then there
>>> are
>>> the implications of large numbers of multigigawatt lasers.
>>>
>>> It was also not clear why you go to the expense of developing Skylon just
>>> to
>>> launch the first satellite.
>>>
>>>
>>> On Tuesday, October 15, 2013, Keith Henson wrote:
>>>>
>>>> http://youtu.be/qCiw99yRBo8
>>>>
>>>> Talk I gave at Google in July.
>>>>
>>>> Keith
>>>>
>
On Tue, Oct 15, 2013 at 4:10 PM, Jake Anderson <jake@xxxxxxxxxxxxxxx> wrote:
> It seems as though one would be better served by building sea dragon to
> launch this rather than skylon.
> you need what 20 sea dragons to get that mass into orbit?
> Once you are done I think you might have a more useful/novel end result,
> launching the entire ISS in one hit with 100T to spare?
>
> I'd be curious to see if a modern take on sea dragon could do better in
> terms of construction price, filament wound fibreglass rather than welded
> steel might well reduce the labour costs of making the thing.
>
> I can see skylon being the taxi of space, great for people and small
> cargoes, because you can test the crap out of it. Not the vehicle of choice
> to deliver a power station however.
>
>
>
> On 16/10/13 02:08, Keith Henson wrote:
>>
>> On Mon, Oct 14, 2013 at 10:40 PM, Derek Clarke <derek_c@xxxxxxxxx> wrote:
>>>
>>> Nice try, but no cigar. That programme is far too expensive.
>>
>> So far, the technical people say it is to expensive and the finance
>> people say it can't be done for technical reasons.
>>
>> Now, *I* have no idea of how to raise that scale of money, but as
>> energy project go, it is about half the size of the largest and there
>> are several of the same size, mostly LNG projects. If the Chinese do
>> it, $60 B is twice the cost of Three Gorges Dam.
>>
>>> Then there are
>>> the implications of large numbers of multigigawatt lasers.
>>
>> That I clearly state in the talk. Even one of them has huge
>> implications. Someone with experiences in military studies says the US
>> will attempt to destroy any Chinese propulsion laser. If the Chinese
>> were doing it jointly with the Indians would we still destroy it? Is
>> it in the interest of the US for the Chinese to get off coal? From the
>> viewpoint of the US, how do propulsion lasers differ in kind from
>> Predator drones and Hellfire missiles?
>>
>>> It was also not clear why you go to the expense of developing Skylon just
>>> to
>>> launch the first satellite.
>>
>> The second generation Skylon, the one with the laser hydrogen heaters
>> is required to get the long term transport cost down. It's just too
>> much of a technological jump at one time so we need the original
>> version. The cargo needed for the first microwave powered propulsion
>> laser is in the ten thousand ton range. That will take ~1000 flights
>> of something to get it there. At two hundred flights per vehicle,
>> that will take 5-6 Skylons and about a year. I don't know any less
>> expensive way to get that much into space, especially when we need the
>> engineering experience of flying a couple of Skylons a day. Working
>> up to 3 flights an hour is going to be an interesting task.
>>
>> Keith
>>
>>> On Tuesday, October 15, 2013, Keith Henson wrote:
>>>>
>>>> http://youtu.be/qCiw99yRBo8
>>>>
>>>> Talk I gave at Google in July.
>>>>
>>>> Keith
>>>>
>>
>> On Mon, Oct 14, 2013 at 10:40 PM, Derek Clarke <derek_c@xxxxxxxxx> wrote:
>>>
>>> Nice try, but no cigar. That programme is far too expensive. Then there
>>> are
>>> the implications of large numbers of multigigawatt lasers.
>>>
>>> It was also not clear why you go to the expense of developing Skylon just
>>> to
>>> launch the first satellite.
>>>
>>>
>>> On Tuesday, October 15, 2013, Keith Henson wrote:
>>>>
>>>> http://youtu.be/qCiw99yRBo8
>>>>
>>>> Talk I gave at Google in July.
>>>>
>>>> Keith
>>>>
>
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